1. Field of Invention
The invention relates to a method of absorbing liquids and sludges. A particularly useful application of the invention relates to absorbing hazardous waste. The method comprises, inter alia, mixing a recycled, starch-based absorbent having an average mesh size greater than 80 mesh with a liquid product to form a composition. Compositions formed by mixing the recycled starch-based absorbent with a liquid waste product can also be included in the invention.
2. Description of the Related Art
Absorption of spilled liquids is a continuous problem for industries that encounter such spills in their normal course of business. This becomes a more acute problem for those industries producing and wishing to contain and/or dispose of hazardous liquid waste, whether or not they have been spilled.
For example, the airline industry is faced with frequent spills of jet fuel or other petroleum products, as well as harsh or potentially environment-damaging chemicals, e.g., cleansers, which are used in routine procedures. Essentially, any industry handling potentially harmful material is subject to legal, economic, and other consequences resulting from delayed, inadequate, or otherwise improper recovery of contaminated or hazardous spills. Potentially harmful products, whether they pose environmental hazards or health threats, are subject to spillage or leakage at any time during their transport or usage, requiring rapid and efficient removal, containment, and disposal in accordance with local, state, or federal laws or regulations. Nearly all manufacturing and transportation industries face similar problems.
A great variety of absorbent materials have been used to soak up liquids, such as flammable liquids, from the ground, from garage floors, roadways and the like. Commonly used absorbents for this purpose include both organic and inorganic materials. Useful organic absorbents include activated carbon, sawdust, wood pulp, paper, peanut hulls, shredded peat moss and similar cellulosic materials. Commonly used inorganic absorbents include clays, pumice, expanded micas, diatomaceous earth, fullers earth and many more. U.S. Pat. No. 4,537,877 summarizes a comprehensive description of solid absorbents, both organic and inorganic, which are used to soak up organic liquids and sets out potential advantages and disadvantages of the various materials.
Many absorbents are not advantageous in the use of spill recovery because of the large volume of absorbent needed to contain the spill. Additionally, the use of some absorbents results in the generation of a much larger volume of hazardous material because of the inability of the absorbent to contain the liquid spill.
Attending to the recovery of spills using inadequate absorbents is labor intensive, costly, and can require one or more workers who are specially trained in recovery of hazardous or contaminated material recovery to be available for rapid deployment. Therefore, there is a need in the art for a lowcost, highly efficient absorbent for the containment of hazardous waste.
Glass-like polysaccharides are well known in the art. These compositions are commonly formulated into abrasive grits for use as blast media in abrasive blasting operations, or fine particulates for use as absorbents in items such as diapers. Abrasive grits typically are hard, angular particles, as opposed to bead or shot, which have more rounded surfaces.
U.S. Pat. Nos. 5,066,335, 5,360,903, 5,367,068, and 6,197,951 describe glass-like polysaccharide abrasive grits and methods for using these grits as blast media to treat surfaces. U.S. Pat. No. 6,159,257 describes a glass-like polysaccharide abrasive grit that addresses a shortcoming of previously described grits, namely, water absorption. U.S. Pat. No. 6,444,653 and U.S. Patent Appl. Pub. No. 2002/0156048 A1, describe glass-like polysaccharide particulate that is useful as an absorbent for liquids. These glass-like polysaccharides are useful as absorbents because of their high capacity to absorb liquids and because they are a recycled product, represent a reusable, thereby cost-effective product to contain hazardous materials.
Therefore, the invention described herein provides for a low cost, highly efficient absorbent useful for absorption of liquids, especially hazardous liquid waste.